php socket uses smtp to send emails with attachments

/**
* php socket smtp send email
* edit: bbs.it-home.org
*/
//define("SOL", "n");
define(" EOL", "rn");
define("SMTP_HOST", "smtp.163.com");//SMTP server
define("SMTP_PORT", "25");//SMTP server port
define("SMTP_USER ", "");//The user account of the SMTP server
define("SMTP_PASS", "");//The user password of the SMTP server
$from = "";//SMTP User email address of the server
$to = "";//Who you want to send to can separate multiple emails with commas
$cc = "";
$bcc = "";
$subject= "This is an email with attachments sent by PHP";//Many clients will have garbled email subject, so convert it
$body = "This is an email sending program with attachments Do you see it? , the HTM tag is displayed here;Please click the link ".date('Y-m-d H:i:s');//Email content
$smtp = new smtp(SMTP_HOST,SMTP_PORT,SMTP_USER,SMTP_PASS, true);//One of these true means authentication is used, otherwise authentication is not used.
$smtp->addAttachment("mail.zip");
$smtp->sendmail($to, $from, $subject, $body, $cc , $bcc);
class smtp {
 /* Public Variables */
 public $attachments = array();
 /* Private Variables */
 private $smtp_host;
 private $smtp_port;
 private $time_out;
 private $host_name;
 private $auth;
 private $user;
 private $pass;
 private $sock;
 /*Contractor */
 public function smtp($smtp_host = null, $smtp_port = null, $user = null, $pass = null, $auth = true) {
 $this->smtp_host = (!empty($smtp_host )) ? $smtp_host : SMTP_HOST;
 $this->smtp_port = (!empty($smtp_port)) ? $smtp_port : SMTP_PORT;
 $this->user = (!empty($user)) ? $user : SMTP_PORT;
 $this->pass = (!empty($pass)) ? $pass : SMTP_PORT;
 $this->auth = $auth;
 $this->time_out = 15;
 #
 $this ->host_name = "localhost";
 $this->sock = FALSE;
 }
 /* Main Function */
 public function sendmail($to, $from, $subject = "", $body = "", $cc = "", $bcc = "") {
 $bndp = md5(uniqid("")) . rand(1000, 9999);
 $bnd = md5(uniqid ("")) . rand(1000, 9999);
 list ($msec, $sec) = explode(" ", microtime());
 $mail_from = $this-> ;strip_line_breaks($from);
 $mail_to = explode(",", $to);
 $body = preg_replace("/(^|(rn))(\.)/", "", $body);
 if ($cc != "") $mail_to = array_merge($mail_to, explode(",", $cc));
 if ($bcc != "") $mail_to = array_merge($mail_to, explode(" ,", $bcc));
 $headers = "MIME-Version:1.0" . EOL;
 $headers .= "To: " . $to . EOL;
 if ($ cc != "") {
 $headers .= "Cc: " . $cc . EOL;
 }
  $headers .= "From: $from<" . $from . ">" . EOL;
  $headers .= "Subject: " . $subject . EOL;
  $headers .= "Date: " . date("r") . EOL;
  $headers .= "X-Mailer: Webmail ver 1.0 (PHP Version/" . phpversion() . ")" . EOL;
  $headers .= "Message-ID: <" . date("YmdHis", $sec) . "." . ($msec * 1000000) . "." . $from . ">" . EOL;
  if (count($this->attachments) > 0) {
   $headers .= "Content-Type: multipart/mixed;" . EOL . chr(9) . " boundary="" . $bndp . """ . EOL . EOL;
   $headers .= '--'.$bndp . EOL;
   $headers .= 'Content-Type : multipart/alternative; boundary="' . $bnd . '"' . EOL . EOL;
   $headers .= '--' . $bnd . EOL;
   $headers .= 'Content-Type: text/plain; charset=utf-8' . EOL;
   $headers .= "Content-Transfer-Encoding: 8bit" . EOL . EOL;
   $headers .= $body . EOL;
   $headers .= '--' . $bnd . EOL;
   $headers .= 'Content-type: text/html; charset=utf-8' . EOL;
   $headers .= "Content-Transfer-Encoding: 8bit" . EOL . EOL;
   $headers .= $body . EOL;
   $headers .= '--' . $bnd . '--' . EOL;
   foreach ($this->attachments as $att) {
    $headers .= "--" . $bndp . EOL . $att;
   }
   $headers .= '--' . $bndp . '--' . EOL;
   $this->clear_attachments();
  } else {
   $headers .= 'Content-Type : multipart/alternative;boundary="'.$bnd.'"' . EOL . EOL;
   $headers .= '--'.$bnd . EOL;
   $headers .= 'Content-Type: text/plain; charset=utf-8' . EOL;
   $headers .= "Content-Transfer-Encoding: 8bit" . EOL . EOL;
   $headers .= $body . EOL;
   $headers .= '--'.$bnd . EOL;
   $headers .= 'Content-type: text/html; charset=utf-8' . EOL;
   $headers .= "Content-Transfer-Encoding: 8bit" . EOL . EOL;
   $headers .= $body . EOL;
   $headers .= '--'.$bnd.'--' . EOL;
  }
  $sent = TRUE;
  foreach ($mail_to as $rcpt_to) {
   $rcpt_to = $this->strip_line_breaks($rcpt_to);
   if (!$this->smtp_sockopen($rcpt_to)) {
    $this->log_write("Error: Cannot send email to " . $rcpt_to);
    $sent = FALSE;
    continue;
   }
   if ($this->smtp_send($this->host_name, $mail_from, $rcpt_to, $headers, $body)) {
    $this->log_write("E-mail has been sent to <" . $rcpt_to . ">");
   } else {
    $this->log_write("Error: Cannot send email to <" . $rcpt_to . ">");
    $sent = FALSE;
   }
   fclose($this->sock);
  }
  $this->log_write("{$mail_to} send over;");
  return $sent;
 }
 public function addAttachment($file, $dispo = "attachment") {
  $file_data = (file_exists($file)) ? file_get_contents($file) : "";
  if ($file_data != "") {
   $filename = basename($file);
   $ext = pathinfo($filename, PATHINFO_EXTENSION);
   $chunks = chunk_split(base64_encode($file_data));
   $parts  = "Content-Type: application/$ext; name="" . $filename . """ . EOL;
   $parts .= "Content-Transfer-Encoding: base64" . EOL;
   $parts .= "Content-Disposition: " . $dispo . "; filename="" . $filename . """ . EOL . EOL;
   $parts .= $chunks . EOL . EOL;
   $this->attachments[] = $parts;
  }
 }
 private function clear_attachments() {
  unset($this->attachments);
  $this->attachments = array();
 }
 /* Private Functions */
 private function smtp_send($helo, $from, $to, $header, $body = "") {
  if (!$this->smtp_putcmd("HELO", $helo)) {
   //$this->log_write("Error: Error occurred while sending HELO command.");
   return FALSE;
  }
  #auth
  if ($this->auth) {
   if (!$this->smtp_putcmd("AUTH LOGIN", base64_encode($this->user))) {
    //$this->log_write("Error: Error occurred while sending HELO command.");
    return FALSE;
   }
   if (!$this->smtp_putcmd("", base64_encode($this->pass))) {
    //$this->log_write("Error: Error occurred while sending HELO command.");
    return FALSE;
   }
  }
  if (!$this->smtp_putcmd("MAIL", "FROM:<" . $from . ">")) {
   //$this->log_write("Error: Error occurred while sending MAIL FROM command.");
   return FALSE;
  }
  if (!$this->smtp_putcmd("RCPT", "TO:<" . $to . ">")) {
   //$this->log_write("Error: Error occurred while sending RCPT TO command.");
   return FALSE;
  }
  if (!$this->smtp_putcmd("DATA")) {
   //$this->log_write("Error: Error occurred while sending DATA command.");
   return FALSE;
  }
  if (!$this->smtp_message($header, $body)) {
   //$this->log_write("Error: Error occurred while sending message.");
   return FALSE;
  }
  if (!$this->smtp_eom()) {
   //$this->log_write("Error: Error occurred while sending . [EOM].");
   return FALSE;
  }
  if (!$this->smtp_putcmd("QUIT")) {
   //$this->log_write("Error: Error occurred while sending QUIT command.");
   return FALSE;
  }
  return TRUE;
 }
 private function smtp_sockopen($address) {
  if ($this->smtp_host == "") {
   return $this->smtp_sockopen_mx($address);
  } else { // bbs.it-home.org
   return $this->smtp_sockopen_relay();
  }
 }
 private function smtp_sockopen_relay() {
  $this->log_write("Trying to Connect " . $this->smtp_host . ":" . $this->smtp_port . "...");
  $this->sock = @fsockopen($this->smtp_host, $this->smtp_port, $errno, $errstr, $this->time_out);
  if (!($this->sock && $this->smtp_ok())) {
   $this->log_write("Error: connenct error" . $errstr . " (" . $errno . ")");
   return FALSE;
  }
  $this->log_write("Connected Ok");
  return TRUE;
 }
 private function smtp_sockopen_mx($address) {
  $domain = preg_replace("/^.+@([^@]+)$/", "1", $address);
  if (!@getmxrr($domain, $MXHOSTS)) {
   $this->log_write("Error: Cannot resolve MX "" . $domain . """);
   return FALSE;
  }
  foreach ($MXHOSTS as $host) {
   $this->log_write("Trying to " . $host . ":" . $this->smtp_port);
   $this->sock = @fsockopen($host, $this->smtp_port, $errno, $errstr, $this->time_out);
   if (!($this->sock && $this->smtp_ok())) {
    $this->log_write("Connect Error ," . $errstr . " (" . $errno . ")");
    continue;
   }
   $this->log_write("Connected to mx host " . $host);
   return TRUE;
  }
  $this->log_write("Error: Cannot connect to any mx hosts (" . implode(", ", $MXHOSTS) . ")");
  return FALSE;
 }
 private function smtp_message($header, $body) {
  fputs($this->sock, $header . "rn" . $body);
  return TRUE;
 }
 private function smtp_eom() {
  fputs($this->sock, "rn.rn");
  return $this->smtp_ok();
 }
 private function smtp_ok() {
  $response = str_replace("rn", "", fgets($this->sock, 512));
  if (!preg_match("/^[23]/", $response)) {
   fputs($this->sock, "QUITrn");
   fgets($this->sock, 512);
   $this->log_write("Error: Remote host returned "" . $response . """);
   return FALSE;
  }
  return TRUE;
 }
 private function smtp_putcmd($cmd, $arg = "") {
  if ($arg != "") $cmd = ($cmd == "") ? $arg : ($cmd . " " . $arg);
  fputs($this->sock, $cmd . "rn");
  return $this->smtp_ok();
 }
 private function strip_line_breaks($address) {
  $address = preg_replace("/([trn])+/", "", $address);
  $address = preg_replace("/^.*<(.+)>.*$/", "", $address);
  return $address;
 }
 public function log_write($message) {
  $message = date("M d H:i:s ") . get_current_user() . "[" . getmypid() . "]: " . $message;
  file_put_contents(dirname(__FILE__) . '/mail.log', $message . PHP_EOL, FILE_APPEND | LOCK_EX);
 }
}